1. Field of the Invention
The invention relates to machines for manufacturing spiral wire bound books or pads on a production basis. A machine of this general type is shown, for example, in Biel et al U.S. Pat. No. 2,973,199.The present invention is concerned primarily with the steps of perforating the book edges and spiral binding the perforated groups. More particularly, the invention is intended to handle relatively thick groups of sheets.
2. Description of the Prior Art
Conventionally, groups of sheets are first perforated along their edges, for example, by a machine such as that shown in Pfaffle, U.S. Pat. No. 3,739,672, and are then fed to a coil binding machine such as shown in Pfaffle U.S. Pat. No. 3,826,290 where they are spiral bound. The conventional manner of handling sheets in these machines is to feed them serially in a single line.
With thicker books, a spiral binding machine such as that shown in U.S. Pat. No. 3,826,290 can bind a substantially greater number of books in a given space of time than the conventional perforating machine can handle. The result is that the production rate can be no greater than the rate at which the perforating machine, whether it be a drilling or punching apparatus, can handle these particular books.